package io.renren.common.utils;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.http.HttpServletRequest;

/**
 * IP地址
 *
 */
public class IpUtils {
	private static Logger logger = LoggerFactory.getLogger(IpUtils.class);

	/**
	 * 获取IP地址
	 *
	 * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
	 * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
	 */
	public static String getIpAddr(HttpServletRequest request) {
        String unknown = "unknown";
        String XRealIp = null;
        String XForwardedFor = request.getHeader("X-Forwarded-For");
        if (StringUtils.isEmpty(XForwardedFor) || unknown.equalsIgnoreCase(XForwardedFor)) {
            XRealIp = request.getHeader("X-real-ip");
        } else {
            String[] XForwardedForArray = XForwardedFor.split(",");
            if (XForwardedForArray.length > 0) {
                XRealIp = XForwardedForArray[0];
            } else {
                XRealIp = request.getHeader("X-real-ip");
            }
        }

        if (StringUtils.isEmpty(XRealIp) || unknown.equalsIgnoreCase(XRealIp)) {
            XRealIp = request.getHeader("Proxy-Client-IP");
        }
        if (StringUtils.isEmpty(XRealIp) || unknown.equalsIgnoreCase(XRealIp)) {
            XRealIp = request.getHeader("WL-Proxy-Client-IP");
        }
        if (StringUtils.isEmpty(XRealIp) || unknown.equalsIgnoreCase(XRealIp)) {
            XRealIp = request.getHeader("HTTP_CLIENT_IP");
        }
        if (StringUtils.isEmpty(XRealIp) || unknown.equalsIgnoreCase(XRealIp)) {
            XRealIp = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (StringUtils.isEmpty(XRealIp) || unknown.equalsIgnoreCase(XRealIp)) {
            XRealIp = request.getRemoteAddr();
        }
        if (XRealIp == null || XRealIp.isEmpty()) {
            return "";
        }
        return XRealIp.equals("0:0:0:0:0:0:0:1") ? "127.0.0.1" : XRealIp;
    }

}
